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• Ensemble output is shown for individual ensemble members for a few parameters.  More importantly, ensemble output showing a selection of individual and combined parameters is presented in a probabilistic or multi-valued format.  The medium range ensemble consists of 50 members plus one control member.  Charts available:
  • Forecast charts (surface and upper air) - showing a selection of individual and combined parameters, to 15days forecast lead-time.
    • Postage stamp charts - to show the output of all ensemble members for a few parameters at several forecast lead-times. (Example chart).
    • Mean and Spread charts - to place the uncertainty measured by the standard deviation of the members of the latest ensemble into the context of recent uncertainty in the ensemble forecasts.  (Example chart).
    • Probability charts - to show probabilities of events exceeding a given threshold (e.g. rainfall > 5mm/day).  (Example chart).
    • Extreme Forecast Index charts (including clickable multiparameter charts) - to highlight areas where forecast values depart significantly from M-climate. (Example chart).
    • Plumes, Meteograms, EFI-CDF, Vertical Profiles - to give probabilistic interpretation of the ensemble for specific locations with optional M-climate data to emphasize departure from the re-forecast climatology.   
    • Cluster charts - to distil ensemble member output into groups exhibiting similar large-scale patterns enabling assessment of most likely results (i.e. possible 'weather scenarios').  (Example chart).
    • Tropical cyclone activity charts (including genesis) - to indicate tropical cyclone threats worldwide. (Example chart).

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Extended range ensemble products are derived from an extension of the normal 15 day ensemble twice per week on Mondays and Thursdays and act as a bridge in time between ensemble forecasts and seasonal forecasts.  The charts available cover week-long periods (i.e. 7-day periods after the data time of the forecast run, going up to day46).   The extended range ensemble consists of 100 members plus one control member.
Charts available:

• Weekly mean anomaly charts - to highlight areas where mean forecast values depart significantly from the ER-M-climate for each location within the chart area. (Example chart).
• Weekly probability anomaly charts - to highlight the probability of differing from the ER-M-climate mean for each location within the chart area. (Example chart).
• Weekly tercile probability charts - to show the probability the weekly mean anomalies will be in lower and upper third of the ER-M-climate for each location within the chart area. (Example chart).Weekly multiparameter outlook charts.
• Weekly averages of the monthly forecast ensemble for several variables on a single chart. (Example chart).Monthly forecast plumes for a selection of European cities. (Example plume).
• Postage stamp charts - to show the output of all ensemble members for a few parameters at several forecast lead-times. (Example chart).
• Weather regime clusters and weather regime time series (based on six seasonal climatological regimes) - to show the more probable flow patterns and predicted changes from one type to another. (Example cluster chart, example time series chart).
• Tropical cyclone probability charts (including genesis) - to indicate tropical cyclone threat and intensity worldwide and compare with tropical cyclone frequency and intensity in the ER-M-climate. (Example chart).
• Time-longitude (Hovmoeller) diagram of the observed and forecast ensemble mean anomaly of 500hPa or 1000hPa geopotential (in dam) in the extra-tropics - to show persistence and progression of disturbances and potential interaction between upper and lower features. (Example diagram).
• Madden-Julian Oscillation (MJO) index metrics and Wheeler-Hendon MJO diagram - to show recent and forecast evolution and uncertainty of MJO features. (Example MJO index metrics Hovmoeller diagram, example Wheeler-Hendon MJO diagram).

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